Steel alloy insensible to hot gases and vapors



Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE IBENNO STRAUSS, OF ESSEN-BRED'ENEY, GERMANY, ASSIGNOR TO FRIED. KRUPP AKTIENGESELLSCHAFT, OF ESSEN-ON-THE-BUHR, GERMANY STEEL ALLOY INSENSIBLE T HOT GASES AND VAPORS No Drawing. Application fileii April 5, 1929, Serial No. 352,912, and in Germany September 21, 1928.

'In the conversion of oil residues to gasoline the steel vessels used to perform the re- ,actions are exposed to the action of the prodnets of decomposition of the oil at elevated 15 temperatures (about 550 degrees C.) and under high pressures (up to 7 0 atm.). As practice has shown, these vessels very soon become short. 7 ject to afford a steel which is renderecl'in- 0 sensible to the action of hot gases and vapors to the process described in my co-pending patent application Serial Number 149,282, filed November 18th, 1926, which new steel ossesses the advantageous property of not 0 ecoming short even when exposed to the action of the products of decompositon of the oils at high temperatures (about 550 degrees C.) and under high pressures (about up to 70 atm.). This object is obtained according to 0 the invention by having the steel alloy used forthe manufacture of the vessels contain about 0.1 to 0.2 per centof carbon, to 12 per cent of chromium, 0.2 to 0.5 per cent of vanadium, with or without to 2 per cent of .5 nickel.

The following steel alloy, e. g. has been i proved to be particularly well suited for the manufacture of the indicated vessels, viz. an alloy containing about 0.15 per cent of carbon.

'0 6 per cent of chromium, 0.3 per cent of vanadium, 2 per cent of nickel.

Vessels made of the above steel alloys do not become shorteven when exposed to high temperatures and pressures in the conversion 5 of oil residues to gasoline. because these steel alloys in a. particularly high degree are free of grain boundaries it treated by the process described in my co-pending patent application Serial Number 149282, filed November -0 18th, 1926. This process consists in heating the alloy above the criticalpoint Ac3 quickly cooling it, and then re-heating to about .600 to 650 C.

I claim;

1. As a new article of manufacture vessels adapted to be used in the conversion of oil residues to gasoline and consisting of an alloy ,that has been heated above the critical point A03. quickly cooled, and re.

50 heated to about 600 to 650 C. said alloy The invention has for its ob-:

being composed of 0.1 to 0.2 per cent of carbon, 5 to 12 percent of chromium, 0.2 to 0.5 per cent of "anadium, the remainder steel.

2. As a new article of manufacture vessels adapted .to be used in the conversion of oil residues to gasoline and consistingof an alloy that has been heated above the critical point A03, quickly cooled, and re-heated to about 600 to 650 C., said alloy being composed of 0.1 to.0.2 per cent of carbon, 5to 12 per cent of chromium. 0.2 to 0.5 per cent of vanadium. to 2 per cent of nickel, the

remainder steel.

3. As a new article of manufacture vessels adapted to be used in the conversion of oil.

residuesto gasoline and consisting of an alloy that has'been heated above the critical point A03, quickly cooled, and 're-heated to about 600 to 650 C., said alloy being composed of 0.15 per cent of carbon. 6 per cent ot chromium.. 2 per cent ot nickel. 0.3 per cent of vanadium, the remainder steel.

The foregoing specification signed at C0- logne, Germany, this th day of March,

BENNO STRAUSS. 

